The present invention relates to semiconductor devices and methods for manufacturing the same, and more particularly to a semiconductor device having a trench-gate field effect transistor and a method for manufacturing the same.
A trench-gate field effect transistor has a structure in which a gate electrode is buried in a trench made in the main surface of a semiconductor substrate through a gate insulating film.
Japanese Unexamined Patent Application Publication No. Hei 7 (1995)-263692 describes a technique for trench MOS gates.
Japanese Unexamined Patent Application Publication No. 2006-324570 describes a technique for a semiconductor device having a trench-gate power MISFET.